Method of coating metal articles



Patented Mar. 20, 1928..

JOHN w. rowann, or immune runny, 0310.

Mullen or COATING METAL ARTICLES.

R0 Drawing.

The invention relates to the decorative coating of metal articles. While in its broader aspects it is unlimited to the coating of any particular metal articles, it is especially applicable to sheets of tin plate used in the manufacture of curtain rods, fixtures, and the like, and will be so ex plained herein. U

When such articles are made from tin plate the customary practice is to provide them with a old-bronze finish. Ordinarily this is done y spraying or otherwise applying a gold-bronze mixture to articles after they have been formed from tin plate.

This is expensive, among other reasons because of the costlmess of the amount of gold-bronze required for the purpose, and because of the necessity of handling a large number of relatively small irregularlyshaped articles.

Various attempts have been made to provide flat or unformed tin plate with a goldbronze finish so as to avoid the necessity of providing articles formed from them with such a finish, but as far as I am aware such attempts have been unsuccessful because the coatings were of such a character that they would crack or flake off when the tin plates were bentor otherwise worked to shape articles from them, and also because the coatingddid not possess the deep dull'color des1re The object of this invention is to provide metal articles, and particularly tin plate, with a deep dull gold-bronze finish which is permanenhand which so closely adheres to tin plate that the plate may be bent or otherwise worked to form various articles from it without in any way impairing the 4d finish.

. The invention is based upon my discovery, made at the. end of extended experiments, that .its stated objects may be attained by first applying to a metal article a coating comprising a mixture of lacquer and gold-bronze, and thereafter applying at least one, but preferably a plurality of coatin s of a mixture of Chmawood oil and go 'd-bronze, and baking the article after the a plication of the first and each of the said p urality of coatings. From this it will be understood that the article is first coated with a mixture comprising lacquer and gold bronze, is'then baked, is then coated with a mixture comprising Chinawood oil and spirits bein Application filed December 81, 1926. Serial N0. 158,415.

gold-bronze, is then again baked, and is then again coated with the second'named mixture and baked, there being preferably two coatings of the last mentioned mixture each followed by a baking. I have found that much better results are attained when each of the bakings is'efiected in an oven in which the coated articles are subjected to indirect circulating heat, such as by heated air, than when subjected to heated products of combustion of fuel gas or the like which prejudicially affect the finish.

By way of example, and not of limitation,

the coating process may be efiected in the following manner: The mixture of lacquer and gold-bronze used for the first coating may be made in the proportion of about 1 pound of pale gold-bronze powder 'with whlch about A, pint of amylacetate is mixed as a solvent, to about 5 gallons of Roman gold lacquer, about 5 gallons of brass acquer and about 1% gallons of special spirits as a reducing medium, the special a' by-product cut of coal oil having a' aum gravity of about 38.8. This, or an equivalent mixture containin lacquer and gold-bronze, may be applie to tin plate by passing the plate between rolls to which the mixture is supplied. Preferably the coating is applied to but one side of a tin plate at a time, the coating as well as the baking procedure beingrepeated for the other side when it is desired to finish both sides of the plate.

After the application of the foregoin mixture, the coated tin, plate is baked pre erably in a continuous oven to whichvariably heated air is supplied. Ovens of this type are quite well known in this art, and accordingly not illustrated herein. Very satisfactory results have been obtained by using a continuous oven 84 feet in length.

in which the temperature of the heated air is maintained at about 240 F. for about the first 4O feet'of travel of the coated plate through the oven, and at about 300 F. for

which is mixed with about pint of amylacetate as a solvent, to about 2 gallons of Chinawood oil and about 2 gallons of naphtha. Each coating of this mixture may be a plied to the previouslv coated and bake tin plate by passing it through rolls in the .manner prevlously explained, and

of the tin late coated with the each bakin d oil and go d-bronze mixture is Chinawoo preferably efiected in a continuous oven in of Chinawood oil and gold-bronze, and-to' bake the tin plate after the application of each coating of this mixture. By applying a third coating of this mixture and again baking the tin plate, the resulting tgoldbronzefinish may be given greater epth and attractiveness A large amount of tin plate coated according to this invention has been fabricated into with a ld-bronze 'tofore curtain rods and various other fixtures without in any way impairing the gold-bronze finish, and in addition to this substantial advantage of the process, the cost of manufacture of articles made from tin plate and having" a old-bronze finish is materially reduced. e coating ma be efiected rapidly and in large volume while the tin plate is flat, and the amount of gold-bronze ,re-

uired for the coating is much less than t at required for rovidin .metal articles ish in t e manner hereone. According to the rovisions of the patent statutes, 1 have exp ained the princip e and operation of m invention, and have described in detai the preferred manner of practicing it and the relative proportions of the ingre lents used in the coating m1xture. However, I desire to have 1t understood that, withln the scope of the appended claims, the invention may be racticed otherw se thantas herein specificaly described.

I claim as my invention:

1. The method of providing a metal arti-' cle with a permanent closely adherent goldbronze finish, comprising applyin to the article first a coating of a.mixture 0% lacquer and gold-bronze, and then a plurality of coatings of a mixture of Chinawoo'd oil and gold-bronze, and bakin the article after the a plication of each 0 said coatings.

2. he method of providing a metal article with a permanent closely adherent goldbronze finish, comprising applying to the article first a coating of a mixture of lacquer and gold-bronze, and then a plurality of coatings of a mixture of Chinawood oil and gold-bronze, and baking the article after the application of each of said coatings by heat derived from direct contact with heated air.

3; The method of providing flat tin plate with a permanent closely adherent goldbronze finish, comprising applying to the tin I quer and g0ld-bronze and then a pluralit of coatings of a mixture of Chinawood 011 and gold-bronze, and baking the tin plate :2

after the application of each of said coatings by heat derived from direct contact with heated air.

5. The method of providing flat tin plate with a pennanent closely adherent goldbronze finish, comprisingapplying to the tin plate first a'coating and gold-bronze, and then a :coat of a mixture of Chinawood oil and goldronze, and bakin the. tin plate after the application of each of said coatings.

of a mixture of lacquer In testimony whereof. I sign 111 name. a .JoHiv w. PoivELn- 

